Connecting bod assembly for



1952 H. J. KRATZER CONNECTING ROD ASSEMBLY FOR RADIAL ENGINES OR LIKE OPERATING DEVICES Original Filed May 17, 1941 Reissued Dec. 9, 1952 CONNECTING ROD ASSEMBLY FOR RADIAL EN GINESOR LIKE OPERATING DEVICES Herbert J. Kratzer, St. Louis, Mo.

Original No; 2,332,323, dated October 19, 1943 Serial No. 393,869, May 17, 1941;

Application for reissue May 12, 1951, Serial No. 226,063

Matter enclosed in heavy brackets appears in the original patent but-forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

4 Claims.-

This invention relates to improvements in connecting rod assembly for radial engines and is a furthering of the improvements in the structure shown in my copending U. S. application filed September 6, 1938, Serial No; 228,500, for providing a synchronizing crank throw hearing.

The principal object of the present invention is to provide an assembly for a piston connecting rod structure to largely serve as counterweight mass for the engine.

Another object is to support certain of the required gearing of the assembly from the counterweightside of the crank shaft.

A further object is to locate the intermediate gearing of the assembly on the crank shaft counterweight.

A still further object is to carry the intermediate gearing of the assembly within the crank shaft counterweight so-that its axis can be supported in spaced bearings.

Another still further object is to provide a connecting rod assembly with improved means for simultaneously locking all of theconnecting rod pins to the crank throw bearing.

Still another object is to provide an improved connecting rod assembly with a cooperable twopart crank shaft mounting whereby one part of the mounting will telescopingly fit in the other part so that there will be no requirement for any further securance for maintaining the telescoping fitting relation of one part of the crank shaft with the other.

With the foregoing and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement-of parts and in the details of construction' hereinafter described and claimed, it being understood that changes may be made within the scope of what is claimed without departing from the spirit of the invention.

An embodiment Of the invention is illustrated in the accompanying drawing, wherein Figure 1 is a vertical sectional elevation through a radially cylindered engine taken approximately on the line |-l of Figure 2 and showing the invention applied thereto and as forming a part of the engine.

Figure 2 is a fragmentary transverse sectional elevation taken approximately on the line 2-2 of Fig. 1;

Figure 3 is a fragmentary transverse sectional elevation taken approximately on the line 33 of Fig; 2.

Referring by numerals to the accompanying drawing, l designates a crank housing having a fixed end wall 5 and a hub -G projecting outwardly therefrom. Opposed to the wall 5 is a removable end wall 1 having an outwardly extending hub 8 which is in horizontal axial alinement with the hub 6.

Securedv to and. radially extended from the housing t are a series of equally spaced cylinders $2 each having a cooperating piston I 9 and a connecting rod H, the inner end ofeach rod being connected to a common master bearing H by means of respective knuckle pins [3.

The crank shaft I l shown, for aiding in the assembly of the engine and/or the connecting rod assembly, is preferably made of two parts wherein the crank shaft axis comprises a pair of axially aligned shaft lengths i5 and It, the shaft length 55 being journaled in a pair of spaced bearings I? and i8 and the shaft length l6 being journaled in a pair of bearings I 9, Fig. 2.

Integral with the shaft length 15 of the crank shaft is and at right angles thereto, is acrank arm ifl and extended therefrom parallel with the shaft length it, is a hollow crank pin 2| whichis telescopingly engaged over a hollow wrist pin extension 22 which is extended from the crank arm 23 of the crank shaft length it of the crank shaft.

In opposing disposition to the crank pin 2! on thecrank arm 20 is a counterweight it which is hollowed at 2% to enclose a (gear) pinion 23 which is securely fixed to (an axis) a pinion pin ill which is disposed parallel to the crank shaft l4,- said (axis) pin having bearing supports 2s and 2-9 in the counterweight 2s.

One end of the (axis) pinion pin 2? extends from the counterweight 24 and securely fixed thereon such as by keying, is a (gear) pinion it) in mesh with a stationary ring gear 3! and which stationary ring gear may extend from the bearing it? and is stationarily fixed by the key 32 which engages the housing 4. This stationary ring gear 3! as shown, is disposed concentric to the axis'of the crank shaft It.

Rigidly secured or formed integral with the end of'the bearing 1 2 which is adjacent the crank arm 2b is a master gear 33 which is in mesh with the (gear) pinion 26 nested in the counterweight 24.

In mounting this improved assembly to form part of a radial engine, the crank shaft length I5 of the crank shaft [4 is engaged within the housing 4 with the crank shaft length I5 seated in its bearings I! and [8, it of course to be supposed that the intermediate gearing which comprises the (gears) pinions 26 and at having previously been assembled on the counterweight 24, and obviously the (gear) pinion 30 will be seated in meshing engagement with the stationarily fixed gear 3|.

The bearing l2 having the (fixed) master gear 33, may be mounted on the crank pin 2| and as the pistons ii] are mounted in respective cy1in ders, the inwardly extending ends of the connecting rods ll can be secured to the master bearing l2 by respective knuckle pins [3. Obviously, the master bearing I2 is properly oriented on the crank pin 2| before the final longitudinal sliding of the bearing on the crank pin meshes its master gear 33 with the intermediate (gear) pinion 26.

The bearing I2 on the opposite side of the master gear 33 is provided with a concentric shoulder 34 on which a locking ring 35 is seated, said ring having a notch 36 which when positioned in alinement with the pin holes of the bearing l2, will permit introduction of the pins l3 of respective connecting rods in respective pin holes as the notch 36 of the ring is intermittently positioned in alinement with respective pin holes of the bearing, and when the last pin of the connecting rods has been mounted, the ring is positioned with the notch 36 out of register with any one of the pin holes and locked to the bearing.

The crank shaft length [6 is then mounted in the bearings I!) of the end wall I and as the end wall is assembled to the housing 4, care is taken to introduce the wrist pin extension 22 into fitting telescoping engagement with the hollow crank pin 2 I, the securing of the end wall I to the housing holding the two parts of the crank shaft I4 together, with their shaft lengths l5 and I6 in axial alinement without there being any requirement of torsionally tying the two halves of the crank shaft together.

This improved connecting rod assembly provides for the application and use of identical rod connections to all the pistons of a radial engine or pump and the like, and in operation the crank shaft I4 is revolved in the direction of the arrow 31 in Fig. 1, and as the stationary concentric or ring gear 3| is non-rotatable, as the crank shaft is revolved the counterweight (gear) pinion 30 and its (axis) pin or shaft 21 will be revolved around the crank shaft axis or stationary gear 3|.

The (gear) pinion 26 which is also secured to the (axis) pinion pin 21 and carried by the counterweight 24 of the crank shaft M, by reason of being in mesh with the gear 33 which rotates with the master crank pin bearing I2, the amount of rotation imparted tothe (gear) pinion 30 will be carried to the bearing (gear) l2 in a reverse direction by the master gear 33 thereby holding the piston rod pins or connections l3 of the bearing l2 in their original set or oriented positions whereby they will be caused to describe identically true circular orbits in travel, symmetrically centered on respective cylinder [axis] laa'es during each revolution of the crank shaft.

Obviously, the intermediate (gears) pinions 26 and 30 cooperating between the crank pin bearing master gear 33 and the fixed stationary ring or concentric gear 3|, will synchronize the revolving of the crank pin bearing [2 in a reverse direction on its crank pin 21 to exactly the same timed speed as the crank shaft I4 is revolved in an opposite or forward direction.

Owing to the properly oriented position of the crank pin bearing i2 being held and maintained during revolving of the crank shaft l4, it is clear that the pistons and rods of respective cylinders will have identical accelerating and retarding movements throughout the continued operation of an engine or device having radially disposed cylinders, and in consequence, uniformly constructed piston rods can be used throughout.

The gearing as shown, is proportioned to provide a one to one ratio; namely, that the bearing gear 33 is turned one revolution on the crank pin when the crank shaft turns one revolution in the engine bearing. With the intermediate gearing disposed within the counterweight, a particular gear train is required and one in which no two of the four ears comprising the train are of like diameter. The mounting the intermediate gearing within the counterweight or degrees away from the crank pin is desirable and important, for the reason that the masses of the two intermediate gears is greater than the gear mounted on the crank pin, thus the entire weight of all the gearing carried by the crank shaft, favorably counterweighs itself.

With further regard to the gear proportions necessary to maintain a one to one ratio when the intermediate gearing is carried on an axis 180 degrees away from the crank pin, it is apparent that the pitch diameter of master gear 33 bears the same ratio to (gear) pinion 26, as does the pitch diameter of stationary gear 3| to that of (gear) pinion 30. A further obvious requirement is that the sum of the pitch radii of ears 33 and 26) master gear 33 and intermediate pinion 26 must equal the sum of pitch radii of (gears 3| and 30) stationary gear 31 and intermediate pinion 30 plus the distance of the crank throw.

The first requisite relating to ratios determines the constant orientation of crank pin bearing, whereas the difference in the sum of the radii of respective pairs of meshed gears must equal onehalf of the desired piston stroke.

In addition to the foregoing, it is obvious that the invention also goes to another method of synchronizing the rotation of a crank pin bearing on its crank pin comparable with the revolving of the crank shaft, and while one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that particular embodiment or otherwise than by the terms of the appended claims.

The use and operation of my invention are as follows:

By the arrangement above described, I insure that the master bearing with its knuckle pins and connecting rods ilrates about the axis of the crank shaft without rotation, thus the proper relationship between the pistons and connecting rods and the master bearing is maintained at all times.

The master gear which rotates with the master bearing on the crank shaft is substantially greater in radius than the crank throw, thus there is ample space about the master bearing for a large number of knuckle pins and the arrangement of a large number of connecting rods. Heretoiore the one to one relationship has been obtained by providing gears in pairs of equal diameter, for instance, in one early solution of the problem, the master gear on the connecting rod having its radius the same as the crank throw is in mesh with a similar intermediate gear and pinion oppositely disposed on the counterweight so that the two gears mesh in line with the crank shaft axis. Under these circumstances, the outer periphery of both the master gear and the intermediate gear are equally spaced from the axis of rotation of the crank shaft and maximum compactness is achieved. However, this places a If the limit on the diameter of the master gear.

master gear is, as in my design, of a radius great er than the crank throw, then the opposed pinion if in line with the master gear and the axis of the shaft will have its center of rotation, if it meshes with the master gear, at a point further removed from the axis of rotation of the crank shaft than is the master gear. As a result, the outer periphery of the pinion opposed to the master gear will extend far beyond the circle described by the gyration of the master gear. This means a substantial waste in space. It means carrying the cylinders further out from the axis of rotation.

I obviate this difl'iculty by providing the master gear, the stationary gear and the intermediate pinions all of different diameters. In this way it becomes possible to have the circle described by the movement of the outer extremity of the master gear and the circle described by the outer extremity of its meshing intermediate pinions coincide so that minimum crank case diameter results.

This design lends itself especially well to diesel engine design where in the interest of strength and stifiness, the crank pin and the crank shaft usually overlap, that is to say, the radius of the crank pin is usually greater than the crank throw. Under these circumstances, it becomes of the utmost importance to have the master gear of diameter greater than twice the crank throw and this is possible with my arrangement.

The pitch diameter of each gear and pinion is difierent from the pitch diameter of any other gear or pinion.

The sum of the pitch radii of the master gear and the pinion in mesh with it, equals the sum of the pitch radii of the stationary gear, the pinion in mesh with it and the crank throw.

The pitch diameter of the master gear bears the same relation to the pitch diameter of the pinion in mesh with it as does the pitch diameter of the stationary gear to that of the pinion in mesh with it.

The diflerence between the sum of the radii of one meshing gear and pinion pair and the sum of the radii of the mes-hing gear and pinion pair equals ones-half of the piston stroke.

The load placed upon the pinion shaft and the pinions 26 and 30 is, owing to the shock action of each explosion in each cylinder, a heavy vibratory, intermittent reversing action. Therefore, it is of the utmost importance that the pinion pin and the pinion pin bearings be of maximum strength. There is not much room in this gear train. It must be at one side of the crank case because it must not infringe on the space occupied by the connecting rods. The arrangement whereby two separate bearings are provided, spaced apart by one of the bearings is an important arrangement in that it provides maximum strength and maximum resistance to distortion.

What I claim is:

[1. A connecting rod assembly for radial engines comprising a counterweighted crank shaft having a. crank pin bearing with a gear fixed thereon, a fixed gear disposed concentric to the crankshaft axis, and intermediate gearing borne by the counterweight of the crank shaft and meshing with said fixed gears respectively] [2. A connecting rod assembly for radial engines comprising a counterweighted crank shaft having a crank pin bearing with a gear fixed thereon, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing borne by the counterweight of the crank shaft and meshing with said fixed gears respectively and disposed on a projected radial line therewith] [3. A connecting rod assembly for radial engines comprising a crank shaft having a crank pin and a counterweight opposed therefrom, a piston rod bearing mounted on said crank pin and having a gear fixed to one side thereof, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing borne by the counterweight of the crank shaft on a projected radial line with said fixed gears and in mesh therewith] [4. A connecting rod assembly for radial engines comprising a crank shaft having a crank pin and a counterweight opposed therefrom, a piston rod bearing mounted on said crank pin and having a gear fixed to one side thereof, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing borne by the counterweight of the crank shaft on a projected radial line with said fixed gears and in mesh with the near side of respective fixed gears] [5. A connecting rod assembly for radial engines comprising a crank shaft having a crank pin bearing with a gear fixed thereon, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing borne by the crank shaft and meshing with the near side of respective fixed gears, said intermediate gearing being disposed on a projected radial line from the axis of said fixed gears] [6. A connecting rod assembly for radial engines comprising a crank shaft having a crank pin, a piston rod bearing mounted on said crank pin and having a gear fixed on one side thereof, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing meshing with said fixed gears and disposed on a projected radial line from the crank pin, said intermediate gearing being mounted on a common axis and having double bearing support on the crank shaft] [7. In combination, a crank shaft having a crank pin and an opposed counterweight, a hearing mounted on the crank pin and having a gear fixedly secured thereto, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing having double bearing support in the counterweight of said crank shaft and meshing with said fixed gears] [8. In combination, a crank shaft having a crank pin, a, bearing mounted on said crank pin having a, concentrically disposed gear fixedly secured thereto, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing borne by the crank shaft and meshing with said fixed gears, said bearing having a series of radially disposed piston rods pinned thereto in equally spaced relation, and a locking ring carried by said bearing for obstructing outward displacement of the pins of said rods from said bearing] [9. In combination, a, crank shaft having a crank pin, a bearing mounted on said crank pin having a concentrically disposed gear fixedly secured thereto, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing borne by the crank shaft and meshing with said fixed gears, said bearing having a series of radially disposed piston rods pinned thereto in equally spaced relation, and a peripherally notched locking ring carried by said bearing for obstructing outward displacement f the pins of said rods from said bearing] [10. In structure of the class described, the combination of a two part crank shaft each having a shaft axis and a crank arm, a hollow crank pin extending from one crank arm, a wrist pin extending from the other crank arm and telescopingly seated in said hollow crank pin, a counterweight on the hollow crank pin arm disposed diametrically opposite therefrom, a piston rod bearing mounted on the crank pin and having a gear fixedly secured thereto, a fixed gear disposed concentric to the crank shaft axis and intermediate gearing borne by the counterweight of the crank shaft and meshing with said fixed gears respectively, said two parts of the crank shaft being mounted together after the gear of the piston rod bearing has been meshed with its respective intermediate gear] [11. A connecting rod assembly for radial engines comprising a counterweighted crank shaft having a crank pin bearing with a gear fixed thereon, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing borne by the counterweight of the crank shaft and disposed parallel thereto and meshing with said fixed gears respectively] [12. A connecting rod assembly for radial engines comprising a counterweighted crank shaft having a crank pin bearing with a gear fixed thereon, a fixed gear disposed concentric tothe crank shaft axis, and intermediate gearing borne by the counterweight of the crank shaft and disposed parallel thereto and meshing with said fixed gears respectively and disposed on a projected radial line therewith] [13. In a radially cylindered device, a crank shaft having a single crank pin and a counterweight, a piston rod bearing mounted on said crank pin and having a spur gear keyed to one end of the bearing in concentric relation thereto,

a stationarily held ring gear disposed concentric to the crank shaft axis, and intermediate spur gearing carried by the crank shaft counterweight and meshing with the gear of said bearing and said ring gear] [14. In combination, a crank shaft having a crank pin and an opposing counterweight, a bearing for the crank pin having a concentrically disposed gear fixedly secured thereto, a fixed ring gear disposed concentric to the crank shaft axis, and intermediate gearing borne by the crank shaft counterweight and having axes paralleling the crank shaft and comprising a gear meshing with said gear of the crank pin bearing and a gear meshing with said ring gear] [15. In a radially cylindered device, a crank shaft having a crank arm and a single crank pin, a counterweight on the crank shaft disposed opposite to said crank pin, a bearing mounted on said crank pin and having a gear rigidly secured in concentric relation thereto between the crank arm and the bearing a stationarily held ring gear disposed concentric to the crank shaft axis, and intermediate gearing paralleling the crank shaft and borne by the counterweight thereof and meshing with the gear of said bearing and said ring gear} [16. A connecting rod assembly for radial engines comprising a counterweighted crank shaft having a crank pin bearing with a fixed gear thereon, a gear fixed disposed concentric to the crank shaft axis, and intermediate gearing borne by the counterweight of the crank shaft and meshing with said fixed gears respectively, all of said gears having different diameters] [17. A connecting rod assembly for radial engines comprising a crank shaft having a crank pin bearing with a fixed gear thereon, a gear fixed disposed concentric to the crank shaft axis, and intermediate gearing borne by the crank shaft and meshing with the near side of respective fixed gears, all of said gears having different diameters, said intermediate gearing being disposed on a projected radial line from the axis of said fixed gears] [18. A connecting rod assembly for radial engines comprising a counterweighted crank shaft having a crank pin bearing with a gear fixed thereon, a fixed gear disposed concentric to the crank shaft axis, and intermediate gearing borne by the counterweight of the crank shaft and meshing with said fixed gears respectively, said gears and said gearing being differently diametered spur gears] 19. A connecting rod assembly for a radial engine comprising a crank shaft having or crank pin, and u counterweight diametrically opposed to the pin, d crank shaft bearing, a master bearing mounted on the crank pin, a plurality of knuckle pins spaced about the master bearing, a connecting rod pivoted on each knuckle a master gear mounted for rotation with the master bearing, a stationary gear concentric with the crank shaft bearing, concentric pinions mounted on the counterweight, their axis of rotation being in the same plane as the axes of the crank shaft and the crank pin, one pinion being in mesh with the master gear, the other pinion being in mesh with the stationary gear, a pinion pin on which both pinions' are rigidly mounted for rotation in unison, one pinion being enclosed within, the other being at one side of the counterweight, bearings in the counterweight for the pinion pin, one bearing between the two pinions, the other bearing being at the end of the pin furthest from the pinion at the side of the counterweight.

29. A connecting rod assembly for a radial engine comprising a crank shaft having a crank pin, and a counterweight diametrically opposed to the pin, a crank shaft bearing, a master bearinc mounted on the crank pin, a plurality of knuckle pins spaced about the master bearing, a connecting rod pivoted on each knuckle pin, a master gear mounted for rotation with the master bearing, a stationary gear concentric with the crank shaft bearing, concentric pinions mounted on the counterweight, their axis of rotation being in the same plane as the acres of the crank shaft and the crank pin, one pinion being in mesh with the master gear, the other pinion being in mesh with the stationary gear, a pinion pin on which both pinions are rigidly mounted for rotation in. unison, one pinion being enclosed within, the other being at one side of the counterweight, bearings in the counterweight for the pinion pin, one bearing being between the two pinions, the other bearing being at the end of the pin furthest from the pinion at the side of the counterweight, the pitch radius of the master gear being greater than the crank throw.

2!. A connecting rod assembly for radial engines comprising a crank shaft having a crank pin, and a counterweight diametrically opposed to the pin, a crank shaft bearing, a master bearing mounted on the crank pin, a plurality of knuckle pins spaced about the master bearing,

a connecting rod pivoted on each knuckle pin, means for preventing rotation of the master bearing about its axis including a master gear mounted for rotation with the master bearing, a stationary gear concentric with the crank shaft bearing, concentric pinions mounted on the counterweight, their axis of rotation being in the same plane as the axes of the crank shaft and the crank pin, one pinion being in mesh with the master gear, the other pinion being in mesh with the stationary gear, a pinion pin on which both pinions are rigidly mounted for rotation in unison, one pinion being enclosed within, the other being at one side of the counterweight, bearings in the counterweight for the pinion pin, one bearing being between the two pinions, the other bearing being at the other end of the pin furthest from the side of the counterweight, the pitch radius of the master gear being greater than the crank throw, the pitch diameter of the pinion in mesh with the master gear being such that the outer periphery of the master gear and said pinion are equally spaced from the axis of rotation of the crank shaft and the distances from the crank shaft axis to the outermost portions of the pitch circles of the master gear and the pinion in mesh with the master year are substantially equal.

22. In structure of the class described, the combination of a crank case and a two part crank shaft each having a shaft axis and a crank arm, two spaced bearings for each of the parts of the crank shaft, a hollow crank pin extending from one crank arm, a wrist pin extending from the other crank arm and telescopingly seated in said hollow crank pin, the wrist pin and crank pin being loosely engaged and free to move longitudinally when one crank shaft part is longitudinally displaced with respect to the other, a removable housing supporting the bearings for the crank part which carries the wrist pin, a counterweight on the hollow crank pin arm disposed diametrically opposite therefrom, a piston rod bearing mounted on the crank pin and having a gear fixedly secured thereto, a fixed gear disposed concentric to the crank shaft axis, concentric pinions mounted on the counterweight, their axis of rotation being in the same plane as the axes of the crank shaft and the crank pin, one pinion being in mesh with the master gear, the other pinion being in mesh with the stationary gear, a pinion pin on which both pinions are rigidly mounted for rotation in unison, one pinion being enclosed within, the other being at one side of the counterweight, bearings in the counterweight for the pinion pin, one bearing being between the two pinions, the other bearing being at the end of the pin farthest from the pinion at the side of the counterweight.

HERBERT J. KRATZER.

REFERENCES CITED The following references are of record in the file of this patent or the original patent:

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